#include <stdio.h>
double cylinder(double r,double h);
int main()
{
	double r,h;
	scanf("%lf %lf",&r,&h);
	printf("%.3lf",cylinder(r,h));
	return 0;
}
double cylinder(double r,double h)
{
	double volume;
	volume=3.1415926*r*r*h;
	return volume;
}
